diff --git a/speechx/cmake/paddleinference.cmake b/speechx/cmake/paddleinference.cmake
index d1f71f00fe47114b573e33eca1ce8769f5482594..957e423c267e2c6176a4c0fcb4623c8752097e46 100644
--- a/speechx/cmake/paddleinference.cmake
+++ b/speechx/cmake/paddleinference.cmake
@@ -22,6 +22,7 @@ link_directories("${PADDLE_LIB_THIRD_PARTY_PATH}xxhash/lib")
 link_directories("${PADDLE_LIB_THIRD_PARTY_PATH}cryptopp/lib")
 link_directories("${PADDLE_LIB}/paddle/lib")
 link_directories("${PADDLE_LIB_THIRD_PARTY_PATH}mklml/lib")
+link_directories("${PADDLE_LIB_THIRD_PARTY_PATH}mkldnn/lib")
 
 ##paddle with mkl
 set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -fopenmp")
@@ -29,14 +30,16 @@ set(MATH_LIB_PATH "${PADDLE_LIB_THIRD_PARTY_PATH}mklml")
 include_directories("${MATH_LIB_PATH}/include")
 set(MATH_LIB ${MATH_LIB_PATH}/lib/libmklml_intel${CMAKE_SHARED_LIBRARY_SUFFIX}
                  ${MATH_LIB_PATH}/lib/libiomp5${CMAKE_SHARED_LIBRARY_SUFFIX})
+
 set(MKLDNN_PATH "${PADDLE_LIB_THIRD_PARTY_PATH}mkldnn")
 include_directories("${MKLDNN_PATH}/include")
 set(MKLDNN_LIB ${MKLDNN_PATH}/lib/libmkldnn.so.0)
 set(EXTERNAL_LIB "-lrt -ldl -lpthread")
 
 # global vars
-set(DEPS ${PADDLE_LIB}/paddle/lib/libpaddle_inference${CMAKE_SHARED_LIBRARY_SUFFIX} CACHE FORCE "DEPS")
+set(DEPS ${PADDLE_LIB}/paddle/lib/libpaddle_inference${CMAKE_SHARED_LIBRARY_SUFFIX} CACHE INTERNAL "deps")
 set(DEPS ${DEPS}
       ${MATH_LIB} ${MKLDNN_LIB}
       glog gflags protobuf xxhash cryptopp
-      ${EXTERNAL_LIB} CACHE FORCE "DEPS")
+      ${EXTERNAL_LIB} CACHE INTERNAL "deps")
+message(STATUS "Deps libraries: ${DEPS}")
diff --git a/speechx/speechx/base/common.h b/speechx/speechx/base/common.h
index a9303cbbc41f8f0cc61ef3a81a524c0ca63c193b..778c06d76194bf136f01f2097a5f9b1cf3703b9c 100644
--- a/speechx/speechx/base/common.h
+++ b/speechx/speechx/base/common.h
@@ -38,3 +38,6 @@
 #include "base/flags.h"
 #include "base/log.h"
 #include "base/macros.h"
+
+#include "utils/file_utils.h"
+#include "utils/math.h"
\ No newline at end of file
diff --git a/speechx/speechx/base/macros.h b/speechx/speechx/base/macros.h
index d7d5a78d1024b83da3fdc310a3b6383e952c9aef..14332a8065368462a7aac3881137511c7fc8274b 100644
--- a/speechx/speechx/base/macros.h
+++ b/speechx/speechx/base/macros.h
@@ -14,6 +14,9 @@
 
 #pragma once
 
+#include <limits>
+#include <string>
+
 namespace ppspeech {
 
 #ifndef DISALLOW_COPY_AND_ASSIGN
@@ -22,4 +25,8 @@ namespace ppspeech {
     void operator=(const TypeName&) = delete
 #endif
 
-}  // namespace pp_speech
\ No newline at end of file
+constexpr float kFloatMax = std::numeric_limits<float>::max();
+
+const std::string kSpaceSymbol = "\xe2\x96\x81";
+
+}  // namespace ppspeech
diff --git a/speechx/speechx/decoder/CMakeLists.txt b/speechx/speechx/decoder/CMakeLists.txt
index 1df935112e641abe6deaafb8f57b2cb635075c00..0383c3ea0d64ee595d0a3b5795725366565b8f5e 100644
--- a/speechx/speechx/decoder/CMakeLists.txt
+++ b/speechx/speechx/decoder/CMakeLists.txt
@@ -18,6 +18,7 @@ set(BINS
   tlg_decoder_main
 )
 
+message(STATUS "xxxxxxxxxx: " ${DEPS})
 foreach(bin_name IN LISTS BINS)
   add_executable(${bin_name} ${CMAKE_CURRENT_SOURCE_DIR}/${bin_name}.cc)
   target_include_directories(${bin_name} PRIVATE ${SPEECHX_ROOT} ${SPEECHX_ROOT}/kaldi)
diff --git a/speechx/speechx/decoder/param.h b/speechx/speechx/decoder/param.h
index d6ee2705894bac7d396c1e4228adb9fae421656a..ed895aedafe20e0a5e1c8c67a1d5ebde6004cd6b 100644
--- a/speechx/speechx/decoder/param.h
+++ b/speechx/speechx/decoder/param.h
@@ -56,7 +56,9 @@ DEFINE_int32(max_active, 7500, "max active");
 DEFINE_double(beam, 15.0, "decoder beam");
 DEFINE_double(lattice_beam, 7.5, "decoder beam");
 
+
 namespace ppspeech {
+
 // todo refactor later
 FeaturePipelineOptions InitFeaturePipelineOptions() {
     FeaturePipelineOptions opts;
@@ -115,4 +117,5 @@ RecognizerResource InitRecognizerResoure() {
     resource.tlg_opts = InitDecoderOptions();
     return resource;
 }
-}
+
+}  // namespace ppspeech
diff --git a/speechx/speechx/utils/math.cc b/speechx/speechx/utils/math.cc
new file mode 100644
index 0000000000000000000000000000000000000000..fe5c7118958ec7ee92e5110e5fc1777c73285223
--- /dev/null
+++ b/speechx/speechx/utils/math.cc
@@ -0,0 +1,82 @@
+
+// Copyright (c) 2022 PaddlePaddle Authors. All Rights Reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#include "utils/math.h"
+
+#include "base/common.h"
+
+#include <cmath>
+#include <algorithm>
+#include <utility>
+#include <queue>
+
+
+namespace ppspeech {
+
+// Sum in log scale
+float LogSumExp(float x, float y) {
+    if (x <= -kFloatMax) return y;
+    if (y <= -kFloatMax) return x;
+    float max = std::max(x, y);
+    return max + std::log(std::exp(x - max) + std::exp(y - max));
+}
+
+// greater compare for smallest priority_queue
+template <typename T>
+struct ValGreaterComp {
+    bool operator()(const std::pair<T, int32_t>& lhs, const std::pair<T, int32_>& rhs) const {
+        return lhs.first > rhs.first || (lhs.first == rhs.first && lhs.second < rhs.second);
+    }
+}
+
+template<typename T>
+void TopK(const std::vector<T>& data, int32_t k, std::vector<T>* values, std::vector<int>* indices) {
+     int n = data.size();
+     int min_k_n = std::min(k, n);
+
+    // smallest heap, (val, idx)
+    std::vector<std::pair<T, int32_t>>  smallest_heap;
+    for (int i = 0; i < min_k_n; i++){
+        smallest_heap.emplace_back(data[i], i);
+    }
+
+    // smallest priority_queue
+    std::priority_queue<std::pair<T, int32_t>, std::vector<std::pair<T, int32_t>>, ValGreaterComp<T>> pq(ValGreaterComp<T>(), std::move(smallest_heap));
+
+    // top k
+    for (int i = k ; i < n; i++){
+        if (pq.top().first < data[i]){
+            pq.pop();
+            pq.emplace_back(data[i], i);
+        }
+    }
+
+    values->resize(min_k_n);
+    indices->resize(min_k_n);
+
+    // from largest to samllest
+    int cur = values->size() - 1;
+    while(!pq.empty()){
+        const auto& item = pq.top();
+        pq.pop();
+
+        (*values)[cur] = item.first;
+        (*indices)[cur] = item.second;
+
+        cur--;
+    }
+}
+
+}  // namespace ppspeech
\ No newline at end of file
diff --git a/speechx/speechx/utils/math.h b/speechx/speechx/utils/math.h
new file mode 100644
index 0000000000000000000000000000000000000000..452bf089ce3e660b2f2e9f924d520c9e0a3d9ab5
--- /dev/null
+++ b/speechx/speechx/utils/math.h
@@ -0,0 +1,28 @@
+// Copyright (c) 2022 PaddlePaddle Authors. All Rights Reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#pragma once
+
+#include <vector>
+#include <cstdint>
+
+namespace ppspeech {
+
+// Sum in log scale
+float LogSumExp(float x, float y);
+
+template<typename T>
+void TopK(const std::vector<T>& data, int32_t k, std::vector<T>* values, std::vector<int>* indices);
+
+}  // namespace ppspeech
\ No newline at end of file